Melchizedek was a shadow (or type) of Jesus.
Gensis 14 tells how Melchizedek, king of Salem and priest of GOD, blessed Abraham after Abraham's forces returned the captures of the Chedorlaomer alliance, including Abraham's nephew Lot.
On the return home, Melchizedek blessed Abraham:
16 So [Abram] brought back all the cavalry of Sodom, and also brought back his brother Lot and his goods, as well as the women and the people.
17 Then the king of Sodom went out to meet him at the Valley of Shaveh (that is, the King's Valley), after his return from the slaughter of Chedorlaomer and the kings with him. 18 Now Melchizedek the king of Salem brought out bread and wine; he was the priest of God Most High. 19 He blessed Abram and said, “Blessed be Abram of God Most High, Creator of heaven and earth; 20 and blessed be God Most High, who delivered your enemies into your hands.”
Then Abram gave him a tithe of all.
(Genesis 14:16-20 OSB)
Melchizedek was both GOD's priest and a king. He was the first—and only—person in Scripture before Jesus to have both roles. In this way, Melchizedek was an image or representation of what was to come in the person of Jesus. This is a shadow or a type. A biblical is something that points toward (or represents) something else.
In prophesying about Jesus the Messiah, David mentioned this shadow:
1 A psalm by David.
The Lord said to my Lord, “Sit at My right hand,
Until I make Your enemies the footstool of Your feet.”
2 The Lord shall send forth the rod of Your power from Zion,
And rule in the midst of Your enemies.
3 With You is the beginning in the day of Your power,
In the brightness of Your saints;
“I have begotten You from the womb before the morning star.”
4 The Lord swore and will not repent,
“You are a priest forever according to the order of Melchizedek.”
5 The Lord at Your right hand crushed kings in the day of His wrath;
6 He shall judge among the nations; He shall fill them with dead bodies;
He shall crush the heads of many on earth.
7 He shall drink from the brook on the way;
Therefore, He shall raise His head high.
(Psalm 109 :1-7 OSB)
The writer of Hebrews explained the connection between Melchizedek and Jesus, quoting the psalm above:
5:1 Every high priest is selected from among the people and is appointed to represent the people in matters related to God, to offer gifts and sacrifices for sins. 2 He is able to deal gently with those who are ignorant and are going astray, since he himself is subject to weakness. 3 This is why he has to offer sacrifices for his own sins, as well as for the sins of the people. 4 And no one takes this honor on himself, but he receives it when called by God, just as Aaron was.
5 In the same way, Christ did not take on himself the glory of becoming a high priest. But God said to him,
“You are my Son;
today I have become your Father.”
6 And he says in another place,
“You are a priest forever,
in the order of Melchizedek.”
7 During the days of Jesus’ life on earth, he offered up prayers and petitions with fervent cries and tears to the one who could save him from death, and he was heard because of his reverent submission. 8 Son though he was, he learned obedience from what he suffered 9 and, once made perfect, he became the source of eternal salvation for all who obey him 10 and was designated by God to be high priest in the order of Melchizedek.
6:16 People swear by someone greater than themselves, and the oath confirms what is said and puts an end to all argument. 17 Because God wanted to make the unchanging nature of his purpose very clear to the heirs of what was promised, he confirmed it with an oath. 18 God did this so that, by two unchangeable things in which it is impossible for God to lie, we who have fled to take hold of the hope set before us may be greatly encouraged. 19 We have this hope as an anchor for the soul, firm and secure. It enters the inner sanctuary behind the curtain, 20 where our forerunner, Jesus, has entered on our behalf. He has become a high priest forever, in the order of Melchizedek.
7:1 This Melchizedek was king of Salem and priest of God Most High. He met Abraham returning from the defeat of the kings and blessed him, 2 and Abraham gave him a tenth of everything. First, the name Melchizedek means “king of righteousness”; then also, “king of Salem” means “king of peace.” 3 Without father or mother, without genealogy, without beginning of days or end of life, resembling the Son of God, he remains a priest forever.
4 Just think how great he was: Even the patriarch Abraham gave him a tenth of the plunder! 5 Now the law requires the descendants of Levi who become priests to collect a tenth from the people—that is, from their fellow Israelites—even though they also are descended from Abraham. 6 This man, however, did not trace his descent from Levi, yet he collected a tenth from Abraham and blessed him who had the promises. 7 And without doubt the lesser is blessed by the greater. 8 In the one case, the tenth is collected by people who die; but in the other case, by him who is declared to be living. 9 One might even say that Levi, who collects the tenth, paid the tenth through Abraham, 10 because when Melchizedek met Abraham, Levi was still in the body of his ancestor.
11 If perfection could have been attained through the Levitical priesthood—and indeed the law given to the people established that priesthood—why was there still need for another priest to come, one in the order of Melchizedek, not in the order of Aaron? 12 For when the priesthood is changed, the law must be changed also. 13 He of whom these things are said belonged to a different tribe, and no one from that tribe has ever served at the altar. 14 For it is clear that our Lord descended from Judah, and in regard to that tribe Moses said nothing about priests. 15 And what we have said is even more clear if another priest like Melchizedek appears, 16 one who has become a priest not on the basis of a regulation as to his ancestry but on the basis of the power of an indestructible life. 17 For it is declared:
“You are a priest forever,
in the order of Melchizedek.”
(Hebrews 5:1-10; 6:16-7:17 NIV)
Melchizedek received a brief mention in Genesis 14. Yet, Scripture explains why he was included in the Bible story:
- His name means king of righteousness.
- His kingdom meant king of peace.
- As Jesus is eternal, so also Melchizedek has no recorded beginning or end in the Genesis account.
- As Melchizedek was appointed by GOD, along with Aaron and Aaron's sons, so also Jesus, as high priest, was appointed by GOD.
Every detail recorded in Scripture was written for a reason. Look for the reason beyond the reference(s), no matter how small or insignificant they may seem. Often, in so doing, you'll discover wonderful truths.